<!DOCTYPE html>
<html>
  <head>
    <style>
      optgroup {color: red}
      optgroup[disabled]:disabled {color: red}
      optgroup:not([disabled]):not(:disabled) + optgroup {color: green}
      optgroup:not(:disabled) {color: green}
    </style>
  </head>
  <body onload='document.getElementById("ogone").removeAttribute("disabled");'>
    <select size="2">
      <optgroup id="ogone" label="There should be no red" disabled="disabled">
      </optgroup>
      <optgroup id="ogtwo" label="There should be no red">
      </optgroup>
    </select>
  </body>
</html>
